[PATCH] xaudio2: Don't render less than a period of audio

[Andrew Eikum]

Sometimes the ALSA driver will report a very small amount of frames
available after a period signal. There is a bug in OpenAL 1.15 which
will crash the application if alcRenderSamplesSOFT is called with less
than 4 frames. And anyway, we shouldn't incur all of this overhead
just to render a couple of frames. So, just skip the rendering step if
we have less than a period of space available in the driver.

Signed-off-by: Andrew Eikum <aeikum at codeweavers.com>
---
 dlls/xaudio2_7/xaudio_dll.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dlls/xaudio2_7/xaudio_dll.c b/dlls/xaudio2_7/xaudio_dll.c
index 76b4c13..a4a9399 100644
--- a/dlls/xaudio2_7/xaudio_dll.c
+++ b/dlls/xaudio2_7/xaudio_dll.c
@@ -2723,7 +2723,11 @@ static void do_engine_tick(IXAudio2Impl *This)
     }
 
     nframes = This->period_frames * 3 - pad;
-    TRACE("going to render %u frames\n", nframes);
+
+    TRACE("frames available: %u\n", nframes);
+
+    if(nframes < This->period_frames)
+        return;
 
     if(!nframes)
         return;
-- 
2.6.1